The present invention relates to a device for transferring sample holders, or vessels, disposed at a microtiter plate into collecting vessels having compatible dimensions and disposed in cassettes.
Recently, a series of different testing methods has been developed for the determination of free and cell-bound substances (e.g. proteins), which methods are based on the bond of a suitable radioactively marked indicator (e.g. antibody) with the substance to be determined (=radioimmune test RIA). Of particular interest are modifications of such radioimmuno-chemical processes which make it possible to make hundreds of determinations simultaneously in a short period of time.
In some of these processes the substances to be tested are anchored in recesses of standardized, so-called microtiter plates of a soft plastic, provided with 96 recesses per plate. In this way it is possible to treat 96 samples, or a multiple thereof, simultaneously with a radioactive indicator. Methods of this type are used on a large scale for routine analyses in hospitals and for research, e.g. for the determination of hormones, antibodies, enzymes, metabolites, pharmaceuticals, etc., by solid phase radioimmune testing. In other radioimmune test processes, the sample vessels are individual test tubes which are disposed in a microtiter plate that is used as a stand.
In the prior art, the sample vessels are transferred manually into corresponding counting vessels. For the case where the sample vessels constitute the recesses of microtiter plates, the recesses are severed by means of an electrically heated wire and then are individually transferred into counting vessels by means of forceps, or tweezers. It is also possible to obtain individual recesses with associated stands, but these must be inserted and removed manually. Such products are marketed by the Flow and Dynatech Companies.
Such manual transfer of the sample vessels into counting tubes is a very cumbersome and time-consuming operation. This is a particularly weighty factor because the test procedures are otherwise highly automated so that the above-mentioned process steps constitute a large proportion of the total work time required for these procedures. At the same time there exists the danger of mixups or the loss of samples.